Explosive powered bomb release unit



Nov. 17, 1959 T. e. NESSLE-R 2,912,902

EXPLOSIVE POWERED BOMB RELEASE UNIT Filed June 20, 1958 1 s r i 1 a4 :1 E 3 l 1e I I 59 M N": I N0 ea nc L74 L 94 Q [90 P E2o g M 51 INVENTOR. 2 moms s. NESSLER A TTORNEYS United States Patent EXPLOSIVE POWERED BOMB RELEASE UNIT Thomas G. Nessler, Philadelphia, Pa., assignor to the United States of America as represented by the Secretary of the Navy Application June 20, 1958, Serial No. 743,511

5 Claims. (Cl. 89-l.5)

(Granted under Title 35, U.S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon or therefor.

The present invention relates to an explosive operated bomb release unit utilizing an electrical relay and explosively actuated expansible bellows.

Bomb release units now in use rely on an electrically operated spring-powered plunger which is held cocked by a wedge and ball locking device. The plunger is electrically released by solenoid action. Such bomb release units are found to be unreliable under high impact conditions resulting on occasion in inadvertent bomb releases. In addition, such devices are limited in the amount of power immediately available or that which could be made available by modification thereof, thereby limiting their future usefulness.

The present invention overcomes the disadvantages of prior bomb release devices by providing for an electrically initiated explosively powered bellows unit utilizing a miniaturized electrical relay to make the unit reliable and highly resistant to severe vibration and impact conditions. In addition, the inventive device described herein below is reduced substantially in size and weight over existing units and at the same time is capable of substantial power increases to make provision for future developments in bomb release systems. Additional advantages of the present invention arise out of its relative simplicity and the substantial reduction in its cost of manufacture.

Accordingly, it is a first object of the present invention to provide a bomb release unit powered by an explosively operated bellows.

It is another object of this invention to provide an explosively actuated bellows release unit substantially reduced in size and weight over existing release units.

It is still another object of this invention to provide a simplified construction of a bomb release unit utilizing a miniaturized electrical relay and an explosively powered bellows readily incorporated into existing bomb release systems.

Another object of this invention is the provision of a bomb release unit having increased power availability and resistance to high vibration and impact conditions over bomb release units now in use.

The exact nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the annexed drawing in which:

Fig. 1 illustrates a section view of a preferred embodiment of this invention and,

Fig. 2 is the electrical wiring diagram for the device shown in Fig. 1.

Referring now to the drawing wherein like reference characters designate like or corresponding parts through out the views, there is shown in Fig. l the bomb release unit connected by an insulated cable 11 containing a plurality of electrical conductors described hereinbelow to a plug unit 14 for connection into the pilots or bombardiers compartment where there is provided the appropriate electrical switches and indicator lights to be described below. It is understood that actuator unit 10 is located in the bomb bay of the aircraft for bringing about the direct release of bombs or other objects to be dropped.

Actuator unit 10 is constructed of a pair of cylindrical casings 16 and 18 joined at a common end by a gasket 20 between the flange 22 of cylindrical casing 16 and the end wall 24 of casing 18. Casing 18 is provided with an access cover 19 having an opening 19a for cable 11. Bolts 21 may be used to secure cover 19 to casing 18 with a gasket 23 therebetween. Cylindrical casing 16 is elongated and is open at its opposite end where it may be threaded at 26 for accommodating a nut 28 provided with an O-ring 30 fitted into an internal groove 32 thereof. Slidably fitted into the interior of cylindrical casing 16 is a cylindrical ejector casing 34 of smaller diameter and closed at end 36. Casing 34 contains an expansible explosive squib such as the commonly known explosive caterpillar motor 38 which consists of a metallic expansible bellows 40 and a solid cylinder 42 integral with each other and together containing the explosive powder. A resistance element 44 is provided at one end of motor 38 to permit initiation of the explosive powder within motor 38 as is understood in the art. It will be seen that the outer circumference of ejector casing 34 is spaced from the inner surface of cylindrical casing 16 and that in this annular space there is provided a coil or helically wound spring 46 which at one end is coiled against a washer 48 adjacent nut 28 and at the opposite end is abutted against a shoulder 50 of cylindrical element 34. This arrangement biases casing 34 with the explosive caterpillar motor 38 therein in the position illustrated and performs another function to be described further below.

A plurality of threaded bolts 52 through openings 53 in flange 22 of casing 16 maintain casings 16 and 18 rigidly connected to each other. An opening 54 through wall 24 of casing 18 permits the passage therethrough of a rod extension element 56 integral with and extending from ejector casing 34. Extension 56 contacts a member 57 pivoted on shaft 57a connected to armature 58 of relay 59 contained within casing 18. Pivoted member 57 is biased by rod 56 into the position illustrated in solid lines representing the position which would be taken upon energization of relay 59. The position shown in phantom is the normal position of pivoted member 57 when relay 59 is not energized and when ejector casing 34 is removed or disposed in its extended position. Mounted on wall 24 of casing 18 is a mounting block 62 of insulating material for a resilient electrical contact element 64 with conductive tip 65 for completing the electrical circuitry between detonating resistor 44 and an electrical lead 66 which extends from relay 59 and terminates on element 64-. The resiliency of element 64 insures contact between resistor 44 and tip 65 during the most severe shock conditions. Mounted on the outside of wall 24 by a screw 67 or other convenient means is a conductive element 68 in contact with the outer wall of casing 42 for electrically grounding explosive caterpillar motor 38. As is understood in the art, the delivery of a pulse to resistor 44 will detonate the explosive powder within motor 38 thereby resulting in the expansion of bellows 40 with the resulting movement of cylindrical ejector casing 34 in the direction of arrow A compressing spring 46 so that the outside surface of end wall 36 wiil, by contact, cause the direct release of the bomb or other object to be dropped from the aircraft. An insulator block 63 acts as a stop for motor 38.

Relay 59 is illustrated electrically in Fig. 2 and is seen to consist of a solenoid coil 72 and the movable armature 58 described above connected to a pair of movable contacts 73 and 74. Coil 72 is connected between ground and by line 76 to 'the stationary contact'NO of movable contact 74 and to one side of motor 38. The other or ground side of motor 38 is connected by line 78 to lead 80, which is grounded. The stationary contact NO for movable contact 73 is connected through line 82, light bulb 84 which is an indicator light on the pilots dashboard for a purpose to be described further below and line 86 to power supply E1. The stationary contact NC for movable contact 74 is connected to line 88. Movable contact 74 is connected to line 90 through switch S1, intervalometer 92 and line 94 to power supply E2. Intervalometer 92 may be of the typecurrently in use in bomb release systems or any other type well known in the art capable of functioninghere in the manner described below. Armature 5'8 with movable contacts 73 and 74 are shown in their position with relay 59 energized, or with ejector casing 34 mounted in position, correspond ing with lever 57 as shown in solid lines in Fig. 1. When relay 59 is unenergized, and ejector casing 34 is extended, armature 58 is positioned with movable contacts 73 and 74 away from their NO positions and movable contact 74 located in its NC position. With relay 59 unenergized, ejector casing 34 when mounted as shown in Fig. 1 will hold armature 58 in the position as shown in Fig. 2. Leads 80, 82, 88 and 90 extend through cable 11 and plug 14 into the cockpit of the aircraft where power supplies E1 and E2, intervalometer 92, switch S1 and indicator light 84 are located. 1

The operation of the device as described above is as follows: I

When it is desired to release one or more bombs, the pilot closes switch S1 which delivers a pulse from power supply E2 of length determined by intervalometer 92 through line 90, contact 74 to detonate motor 38 and simultaneously through coil 72 to ground, energizing relay59. The explosion of powder within motor 38 immediately thrusts ejector casing 34 in the direction of arrow A and removes rod 56 from its bias of lever 57. But the energization of coil 72 in relay 59 retains armature 58 in its restrained position with the movable con tacts 73, 74 in their NO positions, as illustrated. Intervalometer 92, as is understood in the art, continues the pulse for a specific interval of time to insure that the bomb is away from the bomb bay. Then intervalometer device 92 cuts off the pulse thereby releasing armature 58 which then moves contact 74 into its NC position, and breaking contact through movable contact 73. This action results in light bulb 84 going out, thereby indicating to the pilot that the first bomb is away. The next successive pulse is passed from power supply E2 and intervalometer 92 through line 90 to line 88 of the next (not illustrated) actuation unit for the next bomb. Thus, there is a separate release unit 10 and indicator light 84, if preferred, for each succeeding bomb although only a single power source E2 and intervalometer 92. Helical spring 46 causes the retraction of ejection casing 34 as well as insuring proper contact between rod 56 and pivotal member 57.

It is seen that the apparatus described above combines in a novel fashion an explosive squib or motor with a simple electrical circuit including a relay for insuring positive actuation and at the same time permitting this apparatus to be incorporated into bomb release systems now in use. Unit 10 is substantially smaller in size and weight than the spring powered release units now in use. Furthermore, the nature of its construction and design is such that it is highly resistant to high vibration and impact conditions thereby preventing this device from being actuated inadvertently. Furthermore, because of the use of the explosive squib, there is increased power available for future developments in bomb release systems.

It should be understood of course that the foregoing disclosure relates to only a preferred embodiment of theinvention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

What is claimed is:

1. An explosive powered release unit comprising, in combination, ejector means for delivering the releasing force of the unit, explosive means for powering said ejector means, means for detonating said explosive means, relay means having an armature normally biased to a first position when said relay means are unenergized and normally biased to a second position when said relay means are energized, means carried by said ejector means for holding said armature in said second position prior to said ejector means being powered and freeing said armature for movement to said first position when said ejector means are powered, means for delivering an electrical pulse to said relay means and temporarily energizing the same, and said relay means having means for conducting said electrical pulse for detonating said explosive means only when said armature is' in said second position.

2. An explosive powered release unit comprising, in combination, ejector means for delivering the releasing force of the unit, explosive means for powering said ejector means, electrical means for detonating said explosive means, relay means having an armature normally biased to a first position when said relay means are unenergized and normally biased to a second position when said relay means are energized, a switch having a movable contact connected to said armature for movement therewith to first and second contact positions respectively when said armature is moved to said first and second positions, means carried by said ejector means for holding said armature in said second position prior to said ejector means being powered and freeing said armature for movement to said first position when said ejector means are powered, and means for transmitting an electrical pulse through said switch in said second contact position for detonating said explosive means and releasing said holding means 3. An explosive powered release unit comprising, in combination, ejector means for delivering the releasing force of the unit, explosive means for powering said ejector means, electrical means for detonating said explosive means,.relay means having an armature normally biased to a first position when said relay means are unenergized and normally biased to a second position when said relay means are energized, a switch having a movable contact connected to said armature for movement therewith to first and second contact positions respectively when said armature is moved to said first and second positions, means carried by said ejector means for holding said armature in said second position prior to said ejector means being powered and freeing said armature for movement to said first position when said ejector means are powered, and means for transmitting an electrical pulse through said switch in said second contact position to said electrical detonating means for detonating said explosive means and to said relay means for energizing the same, and said armature being biased to said first position and carrying said contact of said switch therewith to said first contact position upon said ejector means being powered and said electrical pulse terminating.

.4. An explosive powered release unit comprising, in combination, ejector means for delivering the releasing force of theunit, explosive means for powering said ejector means, electrical means for detonating said explosive means, relay means having an armature normally biased to a first position when :said relay means are unenergized and normally biased-to a second position when said relay means are energized, first and second switches having movable 'contactsconnected to said armature for each moving therewith to first and second contact positions respectively when said armature is moved to said first and second positions, means carried by said ejector means for holding said armature in said second position prior to said ejector means being powered and freeing said armature for movement to said first position when said ejector means are powered, means for transmitting an electrical pulse through said first switch with its contact in said second position to said electrical detonating means for detonating said explosive means and to said relay means for energizing the same, said armature being biased to said first position and carrying said contacts of said switches therewith to said first positions upon said ejector means being powered and said electrical pulse terminating, and indicator means responsive to movement of the contact of said second switch to said first position for indicating movement of said armature to said first position from said second position.

5. An explosive powered release unit as set forth in claim 4, wherein said first position of the contact of said first switch provides a continuous electrical circuit for succeeding pulses from said pulse delivering means to a next explosive powered unit.

References Cited in the file of this patent UNITED STATES PATENTS 2,351,336 Hooven June 13, 1944 2,564,209 Murphy Aug. 14, 1951 2,575,071 Rockwell Nov. 13, 1951 2,845,004 Johnson July 29, 1958 

